Night flying times

Stubby wrote:
Doug wrote:

How about "if it is dark out, it is night"? That is what most pilots
use anyway. Or don't define it at all. Just call it night. People know
what night is. The amount of darkness at night varies quite a bit, BTW.
We all know that too. No moon, no snow, no city lights, yeah that's
DARK. And a lit runway in such an environment can present problems you
don't have in a city, with a moon and lots of nearby lighting.


I would like to use the casual definition, but it won't hold up in court
after an accident. Your own insurance company will want to split hairs.


How would this come up in court? If I had an accident at night, with a
passenger, and my insurance company disputed my night currency, how
could they dispute my log entries which demonstrated my currency? I DO
maintain night currency, I log it, but I do not log the timestamp of
when the takeoffs/landings took place.

Or, the FAA could put up a web page with GPS sunrise and sunset times on
it.

You mean like this one?:

http://aa.usno.navy.mil/cgi-bin/aa_pap.pl


"Stubby" wrote in message
...
Bob Noel wrote:
In article ,
Stubby wrote:


There is confusion in regard to which "twilight" times are used to define
night flying. What would be wrong with a change to the FARs that say
something like "Flight occuring an hour after GPS-indicated sunset time
and an hour before GPS-indicated sunrise is defined as night flying"?
(The standard exception for Alaska must be included...)


1) not everyone has GPS
There is no need for a pilot to actual own a GPS. He can look at a
friend's or one at the FBO, etc. But for the price of an hour of
instruction, anyone can purchase his very own GPS. Or, the FAA could put
up a web page with GPS sunrise and sunset times on it.

2) why not use the sunrise/sunset times provided by US Naval
Observatory?
(some means will need to be provided for those without internet access)

On Tue, 8 Nov 2005 10:48:24 -0800, "Bob Gardner"
wrote:

Not so fast, Ron. Amazon is not the place to look....the Government Printing
Office is.

Air Almanac 2005
Defense Dept., Navy, Naval Observatory, Nautical Almanac Office
2004: 908 p.; ill.
"Description: Provides astronomical data for air navigation. Contains
ephemeral data for the year, together with auxiliary tables and graphs, and
a brief explanation of the use of the volume. Presents data for the Sun,
Moon, Aries, planets, and stars.
NOTE: NB1301



a.. S/N: 008-054-00201-3
b.. Price: $61.00 In Stock - Warehouse and Retail (Priced) "
Bob Gardner


Ah, Bob -- we are nit-picking here about 'legalities'.

I am well aware that the "Air Almanac" is the current USNO publication
containing astronomical data. However, the regulations under which we fly
call for referring to the **American** Air Almanac, which has not been
published for a number of years.

So the regulation needs to be changed to bring it into compliance with
current publication titles, and also, in my opinion, should be changed to
take into account local topography.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On Tue, 08 Nov 2005 17:13:07 GMT, Jose wrote:

2. If the purpose of night flying regulations is to require the currency
of special skills when it is "dark", then the times should be adjusted to
reflect local topography. For example, ridges and mountains may cause
darkness to be present earlier than the official sunset time.

I think this is one of those places where judgement comes into play.
We're not talking about much of a temporal difference.

Jose

Well, there are legal, practical and safety issues also. On 29 March 2001
there was a fatal accident involving a Gulfstream at Aspen. They were
executing an approach that was not authorized "at night". "Official"
sunset occurred 33 minutes prior to the accident, so "official" night would
have occurred 3 minutes prior to the accident.

However, according to the NTSB calculations, the sun would have set below
the mountainous terrain about 25 minutes BEFORE official sunset time; and
the shadow for the ridge immediately to the west of the accident site would
have crossed the site 79 minutes earlier than official sunset.

Among the NTSB conclusions was "that the aeronautical definition of “night”
does not adequately describe the conditions under which darkness exists in
mountainous terrain and, therefore, use of this term may not adequately
restrict potentially hazardous flight operations".

The NTSB recommended revisions in this regulatory area, to adequately
address these issues.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

They were
executing an approach that was not authorized "at night". [...]
Among the NTSB conclusions was "that the aeronautical definition of “night”
does not adequately describe the conditions under which darkness exists in
mountainous terrain and, therefore, use of this term may not adequately
restrict potentially hazardous flight operations".

The procedure should then not be authorized "after 79 minutes before
sunsett" or somesuch, if this is a special case. If this is a common
problem however, then yes, a more general solution (which may involve
regulatory or training changes) is called for.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

Bruce Riggs writes:

How would this come up in court? If I had an accident at night, with a
passenger, and my insurance company disputed my night currency, how
could they dispute my log entries which demonstrated my currency?

GPS logs (in my case, at least, and I suspect in others), rental records,
radio tapes, ...

But would they? I asked a long time ago about people logging night
take-offs and only got one person who claimed to do it and a bunch of
"well, it'll probably never be an issue" kind of responses.

--kyler

Ron Rosenfeld wrote:
On Tue, 08 Nov 2005 17:13:07 GMT, Jose wrote:


2. If the purpose of night flying regulations is to require the currency
of special skills when it is "dark", then the times should be adjusted to
reflect local topography. For example, ridges and mountains may cause
darkness to be present earlier than the official sunset time.

I think this is one of those places where judgement comes into play.
We're not talking about much of a temporal difference.

Jose


Well, there are legal, practical and safety issues also. On 29 March 2001
there was a fatal accident involving a Gulfstream at Aspen. They were
executing an approach that was not authorized "at night". "Official"
sunset occurred 33 minutes prior to the accident, so "official" night would
have occurred 3 minutes prior to the accident.

However, according to the NTSB calculations, the sun would have set below
the mountainous terrain about 25 minutes BEFORE official sunset time; and
the shadow for the ridge immediately to the west of the accident site would
have crossed the site 79 minutes earlier than official sunset.

Among the NTSB conclusions was "that the aeronautical definition of “night”
does not adequately describe the conditions under which darkness exists in
mountainous terrain and, therefore, use of this term may not adequately
restrict potentially hazardous flight operations".

The NTSB recommended revisions in this regulatory area, to adequately
address these issues.

The trouble is that you can NEVER write enough regulations to alleviate
poor judgement.


Matt

On Wed, 09 Nov 2005 05:14:53 GMT, Jose wrote:

They were
executing an approach that was not authorized "at night". [...]
Among the NTSB conclusions was "that the aeronautical definition of “night”
does not adequately describe the conditions under which darkness exists in
mountainous terrain and, therefore, use of this term may not adequately
restrict potentially hazardous flight operations".

The procedure should then not be authorized "after 79 minutes before
sunsett" or somesuch, if this is a special case. If this is a common
problem however, then yes, a more general solution (which may involve
regulatory or training changes) is called for.

Jose

I think the combination of this sort of problem, along with the fact that
the wording in the regulations is outdated, speaks for a more general
solution.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

I think the combination of this sort of problem, along with the fact that
the wording in the regulations is outdated, speaks for a more general
solution.

Outdated? In what way is it "outdated" (was good then but things have
changed"?)

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

Stubby wrote:

There is no need for a pilot to actual own a GPS. He can look at a
friend's or one at the FBO, etc. But for the price of an hour of
instruction, anyone can purchase his very own GPS. Or, the FAA could
put up a web page with GPS sunrise and sunset times on it.

AFAIK there is no generally agreed upon "GPS sunrise". I'm guessing each GPS
manufacture has its own proprietary algorithm for determining sunrise/sunset.
That's fine for casual use, but I imagine regulation writers are looking for
something more standard.